Myzus persicae, Macrosiphum euphorbia
Scientific Name:
Scientific Name:
Crops:
Crops:
- Tomato
Biology
Control Method
Biology
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Definition
Aphids are part of the order Hemiptera, polyphagous and cosmopolitan: they are small insects generally measuring between 1 and 4 mm.Their mouthparts form a rostrum. The thorax has six legs. Most adult aphids are wingless, with the exception of some males, as well as some females that are required to change host plants. Their wings are transparent and membranous: the anterior ones are larger than the posterior ones. Aphids secrete a sweet substance called honeydew and are vectors of viral or mycoplasma diseases.
Development Lifecycle
The metamorphosis of aphids is incomplete (hemimetabolous insects). Their life cycle consists of three main stages: egg, larvae and adult.Eggs : small, black, shiny
Larvae: similar to adults, but smaller.
Adults: They have a soft, pear-shaped body and are between 1 and 4 mm in length. Their colouration is variable: green, red, black, pink, yellow, brown or bluish. Woolly aphids are covered with a white waxy secretion similar to cotton wool or wool. Their thorax has six thin legs. The majority of adult aphids are wingless (wingless). Winged individuals have two pairs of membranous, transparent wings.Aphids have an unusual and complex life history that runs over several generations per year. Some aphids spend their lives on the same plant while others change host plants to complete their life cycle. Some species engage in sexual reproduction, others multiply only by parthenogenesis.
Aphids usually overwinter as eggs, hidden between bud scales, crevices in the bark or buried underground. Some ants, which raise aphids for honeydew, shelter the eggs in their nests for the winter. When warm weather returns, they carry them to host plants.
In the spring, the overwintering eggs hatch and the first generation is composed exclusively of wingless females. Once mature (about 8 days at 20 °C), they do not lay eggs but give birth, by parthenogenesis, to small female aphids without wings. During their short life (20 to 30 days), each female can produce 40 to 100 aphids.
During the summer, winged females appear periodically and migrate to other plants to form other colonies.
In the fall, females give birth to winged males and wingless females. After mating, fertilized females lay between one and four eggs that they deposit on the stem of the host plant or in gaps in the bark and buds. The eggs hatch the following spring.
Symptoms
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Aphids form dense colonies on young shoots and under leaves.
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Aphid bites slow plant growth and cause a general lack of resistance.
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The leaves once infested turn yellow, wilt, curl, deformed and may fall off prematurely.
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Aphids produce honeydew that attracts wasps, bees and ants.
Contributing factors
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Temperatures
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Low humidity
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Presence of weeds
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Control Method
Recommended Prophylactic and Cultural Method
- Clean structures and equipment used.
- Ventilate greenhouses.
- Weeding to remove weeds that could be a source of fire.
- Choose varieties that are resistant to viral diseases.
- Avoid sprinkler watering or, failing that, practice it at the end of a sunny morning to allow the foliage to dry. Avoid overwatering.
- Regular observations on sticky yellow chromatic plates and on plants.
- Install insect-proof nets at the openings of the greenhouses.
- Set up an entrance airlock for greenhouses to delay the intrusion of insects.
Chemical method
To fight against aphid infestation, it is advisable to apply a preventive treatment as soon as the first individuals appear.
The wide range of products offered makes it possible to obtain preventive effectiveness against attacks by this pest.
